1Key Laboratory for Agro-Ecological Processes in Subtropical Region, and Hunan Research Center of Livestock & Poultry Sciences, and South-Central Experimental Station of Animal Nutrition and Feed Science in Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, Hunan-410125, P.R. China
2Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Estado de México, Mexico
3Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
4Hunan Youtell Biochemical., Ltd, Yueyang, China
5Wuhan Sunhy Biological Co., Ltd, Wuhan, China
6Guangdong VTR Biological Technology Co., Ltd., Zhuhai, China;
7Faculty of Agriculture (El-Shatby), Alexandria University, Egypt
Institute of Subtropical Agriculture, The Chinese Academy of Sciences Changsha, P.O. Box 10, Hunan 410125, P.R. China
*Corresponding author: zltan@isa.ac.cn
#This paper is part of the special issue entitled: Exogenous Enzymes in Animal Nutrition - Benefits and Limitations, Guest Edited by A.Z.M. Salem and N. Odongo, and Editor for Animal Nutrition and Feed Technology, A.K. Pattanaik.
In vitro fermentation experiments were conducted to investigate the effects of 3 sources of exogenous cellulase products (EC) at 4 dose rates (DR) (0, 12, 37 and 62 IU/g of DM) on degradation of forage and methane production by mixed rumen micro-organisms of goats. The maximum gas production (Vf) of grasses was higher (P<0.001) in Neocallimastix patriciarum (NP) group than those in Trichoderma reesei (TR) and Trichoderma longibrachiatum (TL) groups. Quadratic increases in dry matter degradation (DMD) of forage and neutral detergent fiber (NDFD) of straw were observed for all EC, with optimum DR in the low range. Supplementation of EC originated from TR and NP increased (P<0.001) DMD of forage compared to that from TL. Addition of EC originated from TR and NP also decreased pH value, ammonia nitrogen (NH3-N) and methane (CH4) production compared to that from TL. Quadratic decreases in pH value, NH3-N and CH4 of forage were noted for EC of TR and NP, and with optimum DR in the low range. For short chain fatty acid, the EC of NP increased total volatile fatty acid (TVFA) and acetate concentration and the ratio of acetate to propionate of forage compared with EC of TL and TR, and with optimum DR in the low to medium range. It was concluded that the source of EC differed in fiber degradation and methane emission, and with optimum DR of TR in the low range (from 12 to 37 U/g DM) in improving fiber degradation and decreasing methane emission.
Forage, Exogenous cellulase, In vitro fermentation, Methane production
